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Novel Low Cost, High Reliability Wind Turbine Drivetrain

Description: Clipper Windpower, in collaboration with United Technologies Research Center, the National Renewable Energy Laboratory, and Hamilton Sundstrand Corporation, developed a low-cost, deflection-compliant, reliable, and serviceable chain drive speed increaser. This chain and sprocket drivetrain design offers significant breakthroughs in the areas of cost and serviceability and addresses the key challenges of current geared and direct-drive systems. The use of gearboxes has proven to be challenging; the large torques and bending loads associated with use in large multi-MW wind applications have generally limited demonstrated lifetime to 8-10 years [1]. The large cost of gearbox replacement and the required use of large, expensive cranes can result in gearbox replacement costs on the order of $1M, representing a significant impact to overall cost of energy (COE). Direct-drive machines eliminate the gearbox, thereby targeting increased reliability and reduced life-cycle cost. However, the slow rotational speeds require very large and costly generators, which also typically have an undesirable dependence on expensive rare-earth magnet materials and large structural penalties for precise air gap control. The cost of rare-earth materials has increased 20X in the last 8 years representing a key risk to ever realizing the promised cost of energy reductions from direct-drive generators. A common challenge to both geared and direct drive architectures is a limited ability to manage input shaft deflections. The proposed Clipper drivetrain is deflection-compliant, insulating later drivetrain stages and generators from off-axis loads. The system is modular, allowing for all key parts to be removed and replaced without the use of a high capacity crane. Finally, the technology modularity allows for scalability and many possible drivetrain topologies. These benefits enable reductions in drivetrain capital cost by 10.0%, levelized replacement and O&M costs by 26.7%, and overall cost of energy by 10.2%. This design was achieved by: (1) performing an extensive optimization study ...
Date: September 13, 2012
Creator: Chobot, Anthony; Das, Debarshi; Mayer, Tyler; Markey, Zach; Martinson, Tim; Reeve, Hayden et al.
Partner: UNT Libraries Government Documents Department

PowerJet Wind Turbine Project

Description: PROJECT OBJECTIVE The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energy’s objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds. The test model will continue to operate beyond the time frame of the project, with the ultimate goal of manufacturing and marketing the PowerJet worldwide. Increased Understanding of Electronic & Mechanical Controls Integrated With Electricity Generator The PowerJet back plate begins to open as wind speed exceeds 13.5 mps. The pressure inside the turbine and the turbine rotational speed are held constant. Once the back plate has fully opened at approximately 29 mps, the controller begins pulsing back to the generator to limit the rotational speed of the turbine. At a wind speed in excess of 29 mps, the controller shorts the generator and brings the turbine to a complete stop. As the wind speed subsides, the controller releases the turbine and it resumes producing electricity. Data collection and instrumentation problems prevented identification of the exact speeds at which these events occur. However, the turbine, controller and generator survived winds in excess of 36 mps, confirming that the two over-speed controls accomplished their purpose. Technical Effectiveness & Economic Feasibility Maximum Electrical Output The output of electricity is maximized by the integration of an electronic controller and ...
Date: November 30, 2008
Creator: Bartlett, Raymond J
Partner: UNT Libraries Government Documents Department

2012 Market Report on U.S. Wind Technologies in Distributed Applications

Description: At the end of 2012, U.S. wind turbines in distributed applications reached a 10-year cumulative installed capacity of more than 812 MW from more than 69,000 units across all 50 states. In 2012 alone, nearly 3,800 wind turbines totaling 175 MW of distributed wind capacity were documented in 40 states and in the U.S. Virgin Islands, with 138 MW using utility-scale turbines (i.e., greater than 1 MW in size), 19 MW using mid-size turbines (i.e., 101 kW to 1 MW in size), and 18.4 MW using small turbines (i.e., up to 100 kW in size). Distributed wind is defined in terms of technology application based on a wind project’s location relative to end-use and power-distribution infrastructure, rather than on technology size or project size. Distributed wind systems are either connected on the customer side of the meter (to meet the onsite load) or directly to distribution or micro grids (to support grid operations or offset large loads nearby). Estimated capacity-weighted average costs for 2012 U.S. distributed wind installations was $2,540/kW for utility-scale wind turbines, $2,810/kW for mid-sized wind turbines, and $6,960/kW for newly manufactured (domestic and imported) small wind turbines. An emerging trend observed in 2012 was an increased use of refurbished turbines. The estimated capacity-weighted average cost of refurbished small wind turbines installed in 2012 was $4,080/kW. As a result of multiple projects using utility-scale turbines, Iowa deployed the most new overall distributed wind capacity, 37 MW, in 2012. Nevada deployed the most small wind capacity in 2012, with nearly 8 MW of small wind turbines installed in distributed applications. In the case of mid-size turbines, Ohio led all states in 2012 with 4.9 MW installed in distributed applications. State and federal policies and incentives continued to play a substantial role in the development of distributed wind projects. In ...
Date: August 6, 2013
Creator: Orrell, Alice C.; Flowers, L. T.; Gagne, M. N.; Pro, B. H.; Rhoads-Weaver, H. E.; Jenkins, J. O. et al.
Partner: UNT Libraries Government Documents Department

Faculty Recital: 2001-03-07 - Faculty Woodwind Recital

Description: Faculty ensemble performance at the UNT College of Music Recital Hall.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: March 7, 2001
Creator: Sundberg, Terri; Veazey, Charles, 1941-; Scott, John, 1956-; Gillespie, James E. (James Ernest), 1940-; Scharnberg, William; Reynolds, Kathleen et al.
Partner: UNT Music Library

2012 Wind Technologies Market Report

Description: This report describes the status of the U.S. wind energy industry market in 2012; its trends, performance, market drivers and future outlook.
Date: August 1, 2013
Creator: Wiser, R.; Bolinger, M.; Barbose, G.; Darghouth, N.; Hoen, B.; Mills, A. et al.
Partner: UNT Libraries Government Documents Department

Cost-Causation-Based Tariffs for Wind Ancillary Service Impacts: Preprint

Description: Conference paper discussing the integration cost of wind. Although specific tariffs for wind generation for ancillary services are uncommon, we anticipate that balancing authorities (control areas) and other entities will move toward such tariffs. Tariffs for regulation and imbalance services should be cost-based, recognize the relevant time scales that correspond with utility operational cycles, and properly allocate those costs to those entities that cause the balancing authority to incur the costs. In this paper, we present methods for separating wind's impact into regulation and load following (imbalance) time scales. We show that approximating these impacts with simpler methods can significantly distort cost causation and even cause confusion between the relevant time scales. We present results from NREL's wind data collection program to illustrate the dangers of linearly scaling wind resource data from small wind plants to approximate the wind resource data from large wind plants. Finally, we provide a framework for developing regulation and imbalance tariffs, we outline methods to begin examining contingency reserve requirements for wind plants, we provide guidance on the important characteristics to consider, and we provide hypothetical cases that the tariff can be tested against to determine whether the results are desired.
Date: June 1, 2006
Creator: Kirby, B.; Milligan, M. & Wan, Y.
Partner: UNT Libraries Government Documents Department

Wind Shear Characteristics at Central Plains Tall Towers

Description: The objectives of this report are: (1) Analyze wind shear characteristics at tall tower sites for diverse areas in the central plains (Texas to North Dakota)--Turbines hub heights are now 70-100 m above ground and Wind measurements at 70-100+ m have been rare. (2) Present conclusions about wind shear characteristics for prime wind energy development regions.
Date: June 5, 2006
Creator: Schwartz, M. & Elliott, D.
Partner: UNT Libraries Government Documents Department

Wind Powering America Newsletter

Description: Wind Powering America is a nationwide initiative of the U.S. Department of Energy's Wind Program designed to educate, engage, and enable critical stakeholders to make informed decisions about how wind energy contributes to the U.S. electricity supply. As part of Wind Powering America's outreach efforts, the team publishes a biweekly e-newsletter. This postcard is a marketing piece that stakeholders can provide to interested parties; it will guide them to the a website page at which they can sign up for the e-newsletter.
Date: August 1, 2012
Partner: UNT Libraries Government Documents Department